Project Process Design Research For Spent Fuel Reprocessing Plant

Nuclear fuel reprocessing,an essential part of the back-end of nuclear fuel closed cycle,is considered as an important part of the nuclear industry.Nowadays,spent fuel from nuclear plants is increasing quickly which is out of the acceptable spent fuel processing capacity of China.The design and construction of Chinese Commercial Reprocessing Facilities is in preparation.This paper presents the safety precautions and principles for the main reprocessing processes design,expected to be helpful for the future design.The main work is as follows:(1)According to the estimation and statistic of the present and potential spent fuel amount and characteristics discharged from nuclear plants,processing capacity and characteristic parameter of Chinese reprocessing facilities are proposed through appropriate analysis and judgement.(2)Considering the characteristic parameter of spent fuel that is needed to be reprocessed,storage method of spent fuel has been determined.Wet storage process and shearing and dissolution process have been analyzed and studied.(3)It is demonstrated that the main process of nuclear fuel reprocessing facilities should be based on the PUREX process.Uranous Nitrate and Hydroxylamine Nitrate can be used as the reductant with Hydrazine Nitrate as the stabilizer.High acidity process can be used in 1A extraction unit.Uranium finishing facilities can choose double cycle process.The hole process can meet the demands of the nuclear fuel reprocessing facilities.An appropriate process has been proposed according to analysis and comparison results.(4)Safety precautions and principles adopted in the process design are analyzed,and the following research verification and validation work is analyzed from security point of view.The critical safety precautions,such as geometrical shape,the concentration and quantity of fissile material,and neutron poisons,should be considered during design process.The radiolysis safety precautions and non-radioactive safety precautions should be considered simultaneously to ensure the safely and stably operation of the plant.(5)In this paper,main difficulties of chemical separation reprocessing process are summarized and focal points of the following research and improvement work is stated.Through the study and analysis of spent fuel storage and reprocessing process,the process design solution for main process of Chinese spent nuclear fuel reprocessing facilities has been designed,providing some reference to the future process design of nuclear fuel facilities.